Two pictures of navigation device. It is not classical paper map navigation device with two sticks running up-down and left-right to form cross in front of map to show your position on the map. Problem is, when you prepare paper map for this device, there are more layers of paper and no light from behind could be seen, so it need sticks in front of map and it is usually bigger than this one in MiG-31. Also this one is screwed and I doubt pilot have time to screw it all the time to change maps in it and calibrate device flying and 2+ Mach in distance more than 1000 km. It either have special maps made on special paper for this device and place by technicians before flight for area of flying route with proper measure to cover that area, or this is a device working with map on microfilm also placed with technicians before flight and microfilm could easier cover larger area and could move the map, when plane comes out of area , that pilot could always see, where the plane is.
Although it is mechanical device, it is excellent thing, which show pilot the position of plane on the map in real time and all calculations are made by plane computer. Of course today GPS/GLONASS devices with LCD screens are far better, but this was in use before GPS was created.